docs: add Develop AI agents on Apify page

sources/platform/actors/development/quick-start/build_with_ai.md

@@ -15,6 +15,12 @@ import TabItem from '@theme/TabItem';
 
 This guide provides best practices for building new Actors or improving existing ones using AI code generation tools by providing the AI agents with the right instructions and context.
 
+:::tip Develop AI agents on Apify
+
+Looking to build and deploy AI agents as Actors? See [Develop AI agents on Apify](/platform/actors/development/quick-start/develop-ai-agents) for the full stack - templates, sandboxes, LLM access, and monetization.
+
+:::
+
 The methods on this page are complementary. Start with the [AI coding assistant instructions](#ai-coding-assistant-instructions) or [Actor templates with AGENTS.md](#use-actor-templates-with-agentsmd) to get going, then add [Agent Skills](#use-agent-skills) and the [Apify MCP server](#use-apify-mcp-server) to give your assistant more context and better results.
 
 ## Quick start

sources/platform/actors/development/quick-start/develop_ai_agents.md

@@ -0,0 +1,150 @@
+---
+title: Develop AI agents on Apify
+description: Build and deploy AI agents on Apify with framework templates, sandboxes, OpenRouter for LLM access, and pay-per-event pricing.
+sidebar_position: 4.0
+sidebar_label: Develop AI agents
+slug: /actors/development/quick-start/develop-ai-agents
+---
+
+The Apify platform provides everything you need to build, test, and deploy AI agents. This page walks you through the complete toolkit: templates, sandbox code execution, LLM access through OpenRouter, pay-per-event monetization, and deployment to [Apify Store](https://apify.com/store).
+
+This page covers:
+
+- [**Start from a template**](#start-from-a-template) - Use pre-built Apify Actor templates for popular AI frameworks to scaffold your agent quickly.
+- [**AI Sandbox**](#use-ai-sandbox-for-code-execution) - Run code in an isolated environment at runtime. Useful when your agent needs to execute user-provided or dynamically generated code.
+- [**OpenRouter**](#access-llms-with-openrouter) - Access 100+ LLMs through your Apify account without managing separate API keys.
+- [**Pay-per-event pricing**](#monetize-with-pay-per-event-pricing) - Charge users for specific actions your agent performs, such as API calls or token usage.
+- [**Deploy to Apify**](#deploy-to-apify) - Push your agent to the Apify platform and publish it to Apify Store.
+
+:::tip Build with AI
+
+Looking to use AI coding assistants (Claude Code, Cursor, GitHub Copilot) to help you _develop_ Actors? See [Build Actors with AI](/platform/actors/development/quick-start/build-with-ai).
+
+:::
+
+## Start from a template
+
+The fastest way to start your AI agent is to use one of the Apify Actor templates built on popular AI frameworks. Each template comes pre-configured with the right file structure, dependencies, and the Apify SDK integration.
+
+Available AI framework templates include:
+
+- LangChain - LLM pipelines with chain-of-thought and tool use
+- Mastra - TypeScript-native AI agent framework
+- CrewAI - multi-agent orchestration for complex tasks
+- LlamaIndex - retrieval-augmented generation (RAG) workflows
+- PydanticAI - Python agents with structured, validated outputs
+- Smolagents - lightweight agents from Hugging Face
+- MCP - expose your Actor as an MCP server
+
+Initialize a template with the Apify CLI:
+
+```bash
+apify create my-agent
+```
+
+The command guides you through template selection. Browse all available templates at [apify.com/templates](https://apify.com/templates).
+
+If you don't have the Apify CLI installed, see the [installation guide](/cli/docs/installation).
+
+## Use AI Sandbox for code execution
+
+[AI Sandbox](https://apify.com/apify/ai-sandbox) is an isolated, containerized environment where your AI agent can execute code and system commands at runtime. Your agent Actor starts the sandbox and communicates with it through a REST API or MCP interface.
+
+### Key capabilities
+
+- Code execution - run JavaScript, TypeScript, Python, and bash via `POST /exec` with captured stdout/stderr and exit codes
+- Filesystem access - read, write, list, and delete files through `/fs/{path}` endpoints
+- Dynamic reverse proxy - start a web server inside the sandbox and expose it externally
+- Dependency installation - install npm and pip packages at startup through Actor input
+- Idle timeout - the sandbox automatically stops after a period of inactivity
+- MCP interface - connect directly from Claude Code or other MCP clients for live debugging
+
+### Example workflow
+
+1. Your agent Actor starts the AI Sandbox Actor using the Apify SDK (similar to calling any other Actor)
+1. The agent sends code to execute via the REST API (`POST /exec`)
+1. AI Sandbox runs the code in isolation and returns results
+1. The agent processes results and iterates
+
+:::info Sandbox environment
+
+AI Sandbox runs on a Debian image with Node.js version 24 and Python 3 pre-installed. You can install additional dependencies through the Actor input configuration.
+
+:::
+
+## Access LLMs with OpenRouter
+
+The [OpenRouter](https://apify.com/apify/openrouter) Actor provides access to 100+ LLMs through your Apify account. Supported providers include OpenAI, Anthropic, Google, Mistral, Meta, and more. No separate API keys or billing setup required - all costs are billed as platform usage.
+
+:::caution Paid account recommended
+
+To use the OpenRouter Actor, subscribe to a paying Apify plan. Free-tier accounts may be blocked by anti-fraud protections.
+
+:::
+
+OpenRouter exposes an OpenAI-compatible API, so you can use it with any SDK that supports the OpenAI API format.
+
+### Connect to OpenRouter
+
+Use the Apify OpenRouter proxy endpoint with your Apify token:
+
+```javascript
+import { createOpenRouter } from '@openrouter/ai-sdk-provider';
+
+const openrouter = createOpenRouter({
+    baseURL: 'https://openrouter.apify.actor/api/v1',
+    apiKey: 'api-key-not-required',
+    headers: {
+        Authorization: `Bearer ${process.env.APIFY_TOKEN}`,
+    },
+});
+```
+
+The proxy supports chat completions, streaming, text embeddings, and image generation through vision-capable models.
+
+:::caution Token usage tracking
+
+Pay-per-event pricing can charge users per token. To do this, extract token counts from OpenRouter responses. Check the [OpenRouter Actor README](https://apify.com/apify/openrouter) for the latest guidance on this workflow.
+
+:::
+
+## Monetize with pay-per-event pricing
+
+[Pay-per-event (PPE)](/platform/actors/publishing/monetize/pay-per-event) pricing lets you charge users for specific actions your agent performs. Use `Actor.charge()` from the [JavaScript SDK](/sdk/js/reference/class/Actor#charge) or [Python SDK](/sdk/python/reference/class/Actor#charge) to bill users for events like API calls, generated results, or token usage.
+
+### PPE for AI agents
+
+For AI agents that use OpenRouter, consider these pricing strategies:
+
+- Fixed pricing - charge a flat fee per task or request, regardless of the underlying LLM costs
+- Usage-based pricing - charge per token or per LLM call, passing costs through to users with a markup
+
+Your profit is calculated as:
+
+```text
+profit = (0.8 × revenue) - platform costs
+```
+
+:::note Free-tier protection
+
+If an Actor's net profit goes negative (for example, from free-tier users consuming LLM resources), the negative amount resets to $0 for aggregation purposes. Negative profit on one Actor doesn't affect earnings from your other Actors.
+
+:::
+
+For detailed pricing guidance, see the [pay-per-event documentation](/platform/actors/publishing/monetize/pay-per-event).
+
+## Deploy to Apify
+
+When your agent is ready, deploy it to the Apify platform:
+
+```bash
+apify push
+```
+
+This builds and deploys your Actor. Once deployed, you can:
+
+- Publish to Apify Store - make your agent available to other users and start earning with PPE pricing. See the [publishing documentation](/platform/actors/publishing).
+- Run via API - trigger your agent programmatically through the [Apify API](/api/v2).
+- Set up schedules - run your agent on a recurring schedule.
+
+For more deployment options, see the [deployment documentation](/platform/actors/development/deployment).